"""Reply eligibility from session identity only, never from message contents."""
import re
import unicodedata

APPLICATION_REASON = '企小码系统会话不参与自动回复，已跳过'
GROUP_REASON = '群聊不参与自动回复，已跳过'
APPLICATION_NAMES = frozenset({'企小码', '企小码会话', '企小码会话管理', '企小碼', '企小碼會話管理'})
GROUP_KINDS = frozenset({'group', 'group_chat', 'groupchat', 'chatroom', 'room', '群聊', '群会话'})


def normalize_session_name(value):
    value = unicodedata.normalize('NFKC', str(value or ''))
    return re.sub(r'[\s\u200b-\u200d\ufeff]+', '', value).strip()


def _true(value):
    return value is True or value == 1 or isinstance(value, str) and value.strip().lower() in {'true', '1', 'yes'}


def excluded_session_reason(name='', conv_id='', metadata=None):
    """Only inspect recognized metadata keys. Free text is intentionally ignored."""
    metadata = metadata if isinstance(metadata, dict) else {}
    records = [metadata]
    # Persisted visual DB identities are nested; do not recurse into messages.
    event = metadata.get('database_event')
    if isinstance(event, dict):
        records.append(event)
    names = [name]
    ids = [conv_id]
    for record in records:
        names.extend(record.get(key) for key in ('display_name', 'conv_name', 'conversation_name', 'session_name'))
        ids.extend(record.get(key) for key in ('conv_id', 'conversation_id', 'conversationId'))
    if any(normalize_session_name(value) in APPLICATION_NAMES for value in names if value):
        return APPLICATION_REASON
    for value in ids:
        value = str(value or '').strip()
        if value.upper().startswith('R:') or value.lower().endswith('@chatroom'):
            return GROUP_REASON
    for record in records:
        if any(_true(record.get(key)) for key in ('is_group', 'is_group_chat', 'isGroup')):
            return GROUP_REASON
        for key in ('kind', 'chat_type', 'conversation_type', 'session_type'):
            if str(record.get(key) or '').strip().lower() in GROUP_KINDS:
                return GROUP_REASON
    return ''


def visual_group_title_reason(title, name=''):
    """Match a member count added to the opened title, not a row unread badge.

    A personal nickname ending in '(2)' appears unchanged in the list and title;
    it is not a group. Bare numeric counts require a separately known base name.
    """
    title = normalize_session_name(title)
    name = normalize_session_name(name)
    if not title or '@' in title or name == title:
        return ''
    match = re.fullmatch(r'(.+?)\(([0-9]{1,6})(人|位成员|成员)?\)', title)
    if not match or int(match[2]) < 2:
        return ''
    if match[3] or name and match[1] == name:
        return GROUP_REASON
    return ''